Shock-absorber.



W. F. McNABB.

SHOCK ABSURBER.

APPLICATION man MAR.1|. |915.

A TTOHNEYS WEE@ W'ILLIAM F. XVIGNAB, OF CRTHAGE, MISSURI.

Application flied March 1i., 1916.

Be it known that I, VUMAM F. MGNane, a citizen of the United States` and a resident of Carthage, in the eeuntg.7 'o Jasper and State'of Missouri, have inventer-l a new and Improved f3'heck-Absorber, of whielpitl'u'a following a il'lzll,`cle:ir7 anc` exact descr tion.

This invention relater to shook absorbers especially adapted :For use in eeuu erfion with autcanobili-zsj but it not necessarily limited to this application.

The iii\'ention has for its general. obje C1 to improve and simplify the construct and operation of shock absorbers so as le be reliable and eliicient in use, comparatirely simple and inexpensive to nnnwfacture and keep in operative condition, and so designed that it will automatically maintain its resilieney.

,A more specific object of the inrentien is .the provision of a device which not only En the accompanying dra which illustrates one embodiment et ih-. irvcntuni,

the figure is a central vertical section oi? the shock absorber.

Referring to the drawing, A. designates the cylinder, which has a tubular extension a for forming a guide for the stem Y) oi' the piston B. .Besides acting a guide, the part aris an air compressor cylinderl` and the stem l) is the plunger of the compressor. The piston B comprises an annular' flange b l coper.

and a washer-like member or dis-l; C, ating with the flange to forni the piston head, and the opposed faces oi' the flange gather a channel for receiving an oil-soaked leather packing ring 2. The parts of the piston head are kept together by a nur D. Acting on opposite sides of the piston head are eonnoidal springs E and F which serve te provide the necessary resilieiuautr when Speeeation ei Letters Patent,

Pa-teni'i'ed Bee, 5, 193.6.

Serial No. 83,1322.

there is ne air pressure in the spaces at Opposite sides of the piston head. The upper end ol? the cylinder is closed by a head in the forni of a cap K through which the 'upper stein b2 of the piston extends, there being a gland nut G and a packing ring H fior maintaining an air-tight joint between the piston 'b2 and the cap K, and apaulcing ring; l maintains an air-tiffht joint between the eyinderainl the cap. l ne upper and oi the piston stein is eonneeted at L with 'the vehicle bombl or upper half ol the vehicle supporting springs`v and the cylinder A iS mnnceizefl at M uilh the lower hall of the springs-so that as the body bounds or relauuuls there will be relative reni[nona-toryA umiion or' the piston and cjflimier. The lower end of the pump extension ef the cylinder A is closed by a. plug Nn'liich has an inlet cheek valre w, :For the admission of air to the pun'ip erlinder. The chamber y) oi the pump is connected by passages 71 and p2 with the upper and .lon-er ends of the main cylinder A, and in these ras ages 1r and ,n2 are Chee-lc vales P and Q. which Open toward the cylinder L wher-eb;V air can pass to either end of auch' cylinder 'when the pump plunger descends.. At one side of the lower end oi the. (le-rice is a relief valre- 'liwhich is backed by a spring i', lie tension oi whirh is adjustable by a nnt i" which has an opening whereby air can escape when the valve 3R- opens, due io excessive pump 'f.l"he piston B designed io serve three iurpeses.. viz: To absorb the shock en down` ward stroke and to absorb the rebound on upward stroke and rieewersa and to pump a. maxinunn amount oi' air under high eoinv` pression (as desired) at the lower extremitT of the piston thereby replenisl'iimr the snp? ply oi compressed air exhausted through leakage.

The springs E and F are used in the cylinder for the purposes of prevention of de struction and injnri7 to an)f of the parts when the shock absorber is pnt into action after amY extensive period of inactivity or lack of use as it is almost ii' not entirely iinpractical to contain air under pressure for. an)1 length of time unless the leakage 0f air is replenished. After about nine strokes of `the piston. the tension on the springs should be Ieli. .\e d'l; }T the nir pressure.

The principal features o'E the shock abi sorber are To first provideaemeans of supporting the piston during inactlon and until action occurs 4(which is done'with springs downward from presentvposition of pistonY B, thereby gradually increasing the. air pres 2c sure 'in'upper-.portion of cylinder (the air contained having been previously` compressed by reciprocal action) and gradually absorbing the shock.' This same movement of the cylinder (downward) causes the lower end of the piston rod to draw inwardqa charge of air through the air inlet valvey'rl which opens automatically when the airis drawn inand closes automatically on` first movement toward compression; at the same time the air is drawn in through n, the s compression inlet air valvesP and Q, close automatically until compression occurs, at.

which time they-"both open automatically 'and permit the compressed air to enter the A 36 ports leading to the upper and lower pors tions of the cylinder. Thecompression in both lower and upper portionspf cylinder must be equal at all times as, in theevent air in upper portion of cylinder-'should i 40 leak out more rapidly than inthe lower w'portion, the additional amount of air re-V quired to bring the pressure ,1n the upper portion upto the samef pressure as in the lower portion, will be supplied proportionately faster to the upperpart of the cylinder because there will be less TeSlStance on the.

air inlet valve P 'which will cause it to open first and allow the.A compressed air to enter first at that point until the pressurei'n' upper and lower ends of cylinder is equal, after which time the compressed 'airis furnished to both ends of the cylinder in proportionate quantity according to the maximum air pressure for which the governing blow-oil' valve Ris set. l t The blow-oil or governor valve R is designed to control the maximum -air pressure .which may be desiredV to carry in-the bothl ends o ffthe cylinder. This valve can be ad#V '3Q justcdto blowY off' .orpop .at any desired,4

pressure. i In the event considerableY shock; or vibration has been absorl'iedby'ths shock absorber therewill naturally be an excess of compressed air above the amount required foi-easy riding and when both the upper iny'ention appertaiins, and while I have de vscribed the principle of operation, together i'zth the device which I 4now consider to be and lower portions of the cylinder A have been filled to normal carrying pressure of say eighty pounds, .the pump or compressor end o'l the cylinder compresses the air to ninety pounds, which is teu pounds above the amount of air pressure for which the governor R is set. This excess pressure causes thc valve R to open automatically and cxhaust the excess ten pounds of pressure, (hen closes automatically when the pressure has been reduced to the set eighty pounds.

The means of attaching this shock absorber to the ends of the'. upper and lower spring leaves of an automobile may be designed in a number of ways, but the simple method shown is snllicien't to illustrate the support. Any standard attachment on a shock absorber requires a change of the spring or frame attachmentson an automobile.

The cost of manufacturing this shock absorber will be comparatively low us compared to the manufacturing costs of Various other shock absorbers ofthe air cushion type now on the market, as t'is ot' simple design, requiring very little machine wo'rlc, having few parts and'desgned in Such :Vnmnlier that it can be assembled easily and quickly. A. special feature that is carried out in the design is accessibility7 quick and simple. replacements and low cost of replacement.

. This shock absorber is Seli-lubricating. A small quantity of oil (light oil) poured into the upper and lower halves or portions of the cylinder will automatically circulate the oil throughont the cylinder owing to the al most consent air currents and return of the oil by gravity to a point where it is forced to again circulate through the working parts;

From the connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the artto which the e best embodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may be made Iwhendesired as fall within the `scope of the appended claims.

Having thus described my invention, I

. claim -as new and desire to secure by Letters Patent: ,l

1. A; combined shock absorberandair `compressor comprising a cylinder, a piston therein havingva stern, spring means between the piston and cylinder to yieldingly resist motion in both directions, a cylinder con- 1 VIiected with the first cylinder Vand intowhich .the stem of the piston extends to form an aircompressor, valvecontrolled passages leading from the sur compressor tothe opposite ends oi the first-ment1oned cylinder for sup` foregoing'description taken in 10Q- motion in both directions, a cylinder con-- nected withlthe'frst cylinder and into which the stem of the piston extends to form an air compressor, valve-controlled passages leading from the air compressor to the opposite ends of the Erst-mentioned cylinder lfor supplying air thereto, :iivalif'e-eontrolled inlet for the second-mentioned cylinder, and

a relief valve connected with the second cylinder.

3. As a new artielevof manufacture, a coin.-

hined shock absorber and air compressor in the forni of a unitary structure comprising a cylinder, a piston therein, springs interposed between cach end of the cylinder and the piston, passages leading to both ends of the cylinder, valves in the passages and opening toward the cylinder, a compressor actuated by the relative movement of the v piston and Ycylinder for supplyinglr air to the passages, and a valve-controlled inlet for the com presser.

'l'. As a new article of manufacture, a combined shoel absorber and air compressor in the form of a unitary structure comprising a cylinder, a piston therein, springs interposed betweenl each end of the cylinder and the piston, passages leading toA both ends of the cylinder, valves in the passages and opening toward the cylinder, a compressor actuated by the relative movement ot the piston and` cylinder for supplying air to the passages, a valve-controlled inlet for the` compressor, and a relief valve common to the' said. passages and compressor.

5. A device of the class described comprising a cylinder having a reduced tubular extension, a piston movable in the cylinder and having 'stems extending in opposite directions, one out of the cylinder and the other into the tubular extension to form therewith an air pump, passages leading from the bore of the extension to the opposite ends of the cylinder for supplying air. from the pump to the latter, valves in the said Apassages, anda \'al\'e-controlled inlet for admittinpr air to the said tubulin` extension.`

ln testimony whereof I have signed' my name to this .specification inthe presence of two subscribing witnesses. v

WILLIAM l". McNABB. `Witnesses A. L. THOMAS, EDITH Hamme. 

